Place butter in a large pot or deep skillet and melt over medium-low heat.

Stir often and watch for the butter to change from creamy yellow to a deep amber color.

Once browned, remove from heat to prevent burning.

In a large mixing bowl, combine brown sugar and sugar. Pour in the browned butter, ensuring to scrape off all the browned bits.

Whisk until smooth and shiny. Let it cool for 10 minutes.

Add eggs and vanilla, whisking until smooth and creamy.

Fold in flour, baking soda, and salt. Ensure the dough isn't too warm before adding chocolate and toffee bits.

Fold in chocolate chunks and toffee bits. Chill the dough in the refrigerator, either wrapped in plastic for 24-48 hours or scooped into balls.

Preheat the oven to 350 degrees.

Place cookie balls on a light-colored baking sheet lined with parchment paper.

Bake for 10-13 minutes or until the edges turn lightly golden.

Allow cookies to set up for a few minutes before transferring to a wire rack to cool.